A Numerical Research on Rain Storm Kinetic Process of the Wuhan Area on July 21, 1998
1998年7月21日武汉暴雨小尺度动力特征的数值模拟研究

A three-dimensional non-hydrostatic convective cloud numerical model with fully elastic primitive equations was used to simulate the occurrence and development of the rain-storm in Wuhan, on July 21, 1998. The characteristics of cloud kinetic process and physical quantity flux are analyzed. The results indicate that the special vertical distribution of temperature and humidity is the major cause of this rain-storm. The transport of air with high temperature and humidity from low-level to cloud is the mainly energy source for the development of this rain-storm in a long time. The suitable wind shear, particularly the existence of low-level air flow anti-direction of cloud movement, makes the high temperature and moisture air transport from the front area of cloud at low-level into cloud, and down-wind with dry and low temperature occurring with the rain fall flowing out quickly. Also the upper air jet current supports the flow-out air at the top of convective cloud diffusion far away. This structure of kinetic field maintains the rain-storm for a long time. The analyzed results of divergence field, water vapor flux also furthermore support this conclusion.